1. Field of the Invention
The present invention relates to a disk device for recording and reproducing such as a floppy disk and, more particularly, to a disk device which reduces an impact likely to occur when a magnetic head contacts the disk during loading.
2. Description of Related Art
FIG. 10 is a side view showing a disk device 50 for a floppy disk.
The disk device 50 has a chassis 51, a slide plate 52, and a holder 53. On the chassis 51 is mounted the slide plate 52, which is movable in a longitudinal direction (in a lateral direction in FIG. 10). The slide plate 52 is provided with a holder 53 in which a disk case containing the floppy disk is inserted. The slide plate 52 and the holder 53 are connected by means of a coil spring 56, by which the slide plate 52 is constantly pushed to the left in the drawing.
The slide plate 52 has slide grooves 58a and 58b cut out obliquely in the front and rear portions of the side wall, and projections 55a and 55b formed on the side of the holder 53 slide in engagement with the slide grooves 58a and 58b. 
In the disk device 50 stated above, the slide plate 52 is moved and locked in the right position with the holder 53 in the upper position as shown in FIG. 10. The disk case, when inserted in the direction of the arrow 23 in the drawing, is received by the holder 53. At this time the slide plate 52 is unlocked, and is moved to the left in the drawing by the force of the coil spring 56; accordingly the holder 53 goes downwardly with the projections 55a and 55b sliding in the slide grooves 58a and 58b (same also on the opposite side). At this time, the disk D in the disk case first contacts a magnetic head 54b on the side 0 side, and thereafter a magnetic head 54a on the side 1 side goes downwardly. Thus the disk D is held between the magnetic head 54a and the magnetic head 54b. In this state, data read/write operation is done while the disk D is turning.
To take out the disk case a button 57 is depressed to allow rightward movement of the slide plate 52. The holder 53 rises and the disk case is pushed out for discharge by a discharge member not shown.
In the disk device 50, however, the disk D is likely to get damaged when contacting the magnetic head.
When the disk case is inserted into the disk device 50 until it is held by the holder 53, and is lowered, the disk D in the disk case first contacts the magnetic head 54b on the side 0 side, and thereafter the magnetic head 54a on the side 1 side is lowered until it contacts the disk D. To the magnetic head 54a on the side 1 a spring force is constantly applied to press the magnetic head 54a towards the disk D side. With the insertion of the disk D, the magnetic head 54a thus being pressed comes into a collision with the disk D. That is, the magnetic head 54a collides against the disk D due to the force of the coil spring 56, producing an impactive force with which the disk D is likely to be impaired and accordingly resulting in a failure of data recording and reproduction.
The holder 53 is vertically guided. However, since the coil spring 56 is applying a horizontal force to the slide plate 52, the frictional force in the guide portion increases. Therefore when the disk case is taken out, a great force is needed to push out the button 57 and further there is such an inconvenience that the disk case can not be ejected out if the button 58 is not pushed in to some depth.
In view of the above-described inconvenience, therefore, it is an object of the present invention to provide a disk device which facilitates ejection of the disk case without giving damage to the disk even when the disk inserted contacts the magnetic head.
The disk device of the present invention has a chassis, a holder which moves between a first position where the disk case is received and a second position where the disk in the disk case thus received is set in the rotation drive section, a magnetic head which contacts the disk when the holder has moved as far as the second position, a forcing member for moving the holder towards the second position, and an ejecting member for driving the holder from the second position back towards the first position. In the disk device, a frictional mechanism is interposed between the holder side and the chassis side, for increasing a load for movement when the holder is moved towards the second position.
Adopting the above-described means can decrease the speed of movement of the holder to the second position by applying a load in a different direction of movement of the holder and also decrease the speed of movement of the head when the disk case is inserted into the holder and then the holder moves to the second position. As a result, an impact can be reduced when the magnetic head contacts the magnetic disk surface of the disk case.
In this case, it is desirable that a slide piece be provided as the frictional mechanism, on one of the holder side and the chassis side, with an inclined portion tapered in the direction A in which both sides are oppositely placed, and, on the other side, a counterpart portion on which the slide piece slides, and that the inclined portion slide on the counterpart portion when the holder moves towards the second position.
Because of the constitution of the aforesaid means and the provision of the counterpart portion, e.g., a sliding hole on the chassis side, the inclined portion of the slide piece provided on the holder side slides along the sliding hole when the holder moves to the second position. At this time, a frictional force occurs due to the sliding of the inclined surface on the edge portion of the sliding hole. The frictional force reduces the speed of the holder moving from the first position to the second position, thereby diminishing an impact resulting from the contact of the head with the magnetic disk surface of the disk case. Thus it becomes possible to prevent giving damage to the magnetic disk surface.
When the disk case is to be taken out, the inclined portion slides along the sliding hole and besides an upward force acting on the holder works to move the slide piece upwardly. As a result, the disk case can be taken out by operating with a little force.
Also it is desirable that there should be provided, as the frictional mechanism, a sliding piece on one of the holder side and the chassis side and an elastic member for elastically pressing the slide piece on the other side, and that the slide piece should slide on the elastic member when the holder moves towards the second position.
In this case, the slide piece is a plate spring having a V-shaped or curved portion and the forward end of the slide piece is desired to slide at the inclined portion of the curved portion when the holder moves to the second direction, so that the crest of the curved portion contacts the side portion of the slide piece. And it is desirable that upon the completion of movement of the holder to the second position, the crest of the curved portion contact the side of the slide piece.
Furthermore, in the aforementioned case, the slide piece partly contacts the inclined portion formed in a V shape when the holder starts moving from the first direction to the second direction. Furthermore, with the sliding motion of the slide piece on the plate spring, the plate spring expands to slide while the V-shaped crest of the plate spring is in contact with the side of the slide piece. Consequently, the sliding speed of the holder decreases and accordingly the impact occurring at the time of head contact with the disk is lessened, thereby preventing giving a damage to the disk.
Furthermore, when the disk case is taken out, the holder is slid in the reverse direction, thus moving the slide piece along the crest of the plate spring. When the bottom of the slide piece has reached a higher position than the crest, the slide piece is raised by the force of the plate spring. Consequently, the disk case can be taken out simply by applying a little operating force.
The foregoing object and other objects according to the present invention will become more apparent and understandable from the following detailed description thereof, when read in connection with the accompanying drawings.